Do you remember the movie-the Swamp Thing? If you do, I’d daresay you’re probably at least as old as I am (not that I’m telling!). If you don’t know of it, it’s an interesting science fiction film based on the DC Comics Universe’ story of a humanoid mass of vegetable matter, who fights to protect his swamp home from various threats. Can you imagine what it would be like if we had to handle such a creature in real life! It’d be pretty freaky… but maybe, we’d learn to treat our mangrove swamps with a little more decorum!
It’s a swamp! Why treat it with anything some of u say? Well, yesterday evening, Science Centre Singapore had at its Science in the Café event, the honour of Assistant Professor, Dan Friess from NUS. He regaled an inquisitive audience about the biophysical threats to Southeast Asia’s mangrove swamps.
I was among the captive audience, and was thoroughly engaged! Thanks to him, the plight of mangroves is no longer relegated to the dark, (not so smelly) and possibly mosquito-infested swamp in my brain! :p~ So, what’s a mangrove? Quoting from the mangrove guidebooks that Science Centre has published and which Daniel actively recommends to his students and proudly refers to as the bible on Singapore mangroves:
“The term ‘mangrove’ is used in the broad sense either to refer to the highly adapted plants found in tropical intertidal forest communities or the ecosystem itself. It may have been derived from a combination of the Malay word ‘manggi-manggi’ for a type of mangrove tree (Avicennia) and the Arabic word ‘el gurm’.
Our mangroves, as contrary to popular belief, are not really places where mosquito hordes, poisonous snakes, crocodiles and tigers chill out. Quite a diverse group of plants (over 60 different species at one time including flowering plants) and animals (like anthropods, crustaceans, chelicerates, molluscs, echinoderms and vertebrates) have been sighted at these mangroves.
Have a look at the guidebooks and you’ll see many examples of the different plant and animal groups that make up the mangrove community! Back to the talk, Daniel shared that 75% of Southeast Asia’s mangrove has been lost in the last 100 years at a much faster rate than the loss of rainforest and coral reef. Singapore has lost about 95% of mangrove from pre-colonial times!
The threats that have contributed to this dramatic loss include: pests (like bees!), trash (which choke the roots of trees), marine pollution from ships passing through, storms, land reclamation, the rise in sea level, changing tidal currents (which cause considerable erosion), transboundary pollution, storms, the wake from ships, river pollution and sediment starvation, harvesting and poor genetic connectivity. Quite a list huh? *pout!
If you’re wondering just how the mechanics of each of these factors play out, well… it’s a bit of a story – ‘a talk’ to be exact! But perhaps I’ll briefly touch on a few of them (waves, sea level rise and the change in land use).
Mangroves are affected by waves. If you increase the wave energy, it can go past their threshold and erode them. Strong waves scoop sediments from the roots of trees. In stormy winds, trees then topple over.
Source: Anton Bielousov
2. Sea level rise
The change in sea level, which by the end of 2100, is predicted to go a metre above ground, can cause frequent flooding and just about drown a mangrove (and if like me-you’re thinking that would be perfect for a mangrove, think again!).
3. Changes in land use
Taking Myanmar as a case in point, much of their mangroves were recently lost to deforestation as the country invested in rice paddies as what Daniel considered to be a short term (almost stop-gap) solution to food shortage. In Singapore, the URA 2013 Land Use Plan charts a lot of land that will be reclaimed in the East Coast region amongst other areas of Singapore and this can potentially impact some the remaining mangroves we have on the island.
All this doom and gloom doesn’t really leave us with a pretty picture as Daniel concedes. For wetland scientists and conservationists, it’s that much harder as they have to see their life’s work ‘erode away’ before their very eyes… But there’s something we can do, besides hoping for the Swamp Thing to emerge (where is that fella anyway, just when we need him!).
Mangrove flowering plant
Rather than lobby for our nation to legislate a wetland preserve (which doesn’t really address external stressors on mangroves), we can engage in mangrove engineering and restoration. This is already taking place in Pulau Tekong where the trunks of mangrove trees have been placed to form a wall to dissipate wave energy (like breakwaters I guess). Daniel reckons this NParks effort has been successful to date and so kudos to them!
In understanding the biophysical conditions that aid restoration, we’ll be able to create a physical environment where mangroves can naturally grow without any human intervention. Have a chat with Daniel someday – he’s a lovely chap, pick up one or better still-two of our guidebooks on mangroves at the Science Centre or through our distributor, and maybe get in on the restoration action! It’ll do you good – I just know it will.
Swamp on brother, swamp on!
Dr Daniel Friess is an Assistant Professor at the Department of Geography, National University of Singapore, where he teaches in areas such as Coastal Management, The Biophysical Environment of Singapore and Research Methods in Environmental Sciences. Dan is a wetland scientist, and his research focuses on the physical and anthropogenic factors that determine the stability of mangroves and the ecosystem services they provide. Dan and his lab conduct mangrove research in Thailand and Indonesia, though their research on Singapore’s mangroves is key to understanding how processes may operate in other parts of the region.